时间轴

2026-03-11

init

题目：

P438 找到字符串中所有字母异位词

https://leetcode.cn/problems/find-all-anagrams-in-a-string/?envType=study-plan-v2&envId=top-100-liked

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// 2026.3.11 10:58
#include <vector>
#include <string>

using std::string;
using std::vector;

class Solution {
    public:
        vector<int> findAnagrams(string s, string p)
        {
                int i, index, valid = 0, need_valid = 0;
                int left = 0, right;
                int slen = s.size(), plen = p.size();
                vector<int> need(26, 0);
                vector<int> curr(26, 0);
                vector<int> ret;

                for (i = 0; i < plen; i++)
                        need[p[i] - 'a']++;
                
                for (i = 0; i < 26; i++)
                        if (need[i] > 0)
                                need_valid++;

                for (right = 0; right < slen; right++) {
                        if (right - left + 1 > plen) {
                                index = s[left] - 'a';

                                if (curr[index] == need[index])
                                        valid--;

                                curr[index]--;

                                left++;
                        }

                        index = s[right] - 'a';
                        curr[index]++;

                        if (curr[index] == need[index])
                                valid++;

                        if (valid == need_valid)
                                ret.push_back(left);
                }
                return ret;
        }
};
// 2026.3.11 11:19